This is a difficult issue and to go back to the original question: I don't think it's an absolute no at all, at least it should not be, but whether the situation you or someone else finds themselves in progresses along that route is dependant on many factors. I have never had to deal with this myself, so perhaps I'm not a good judge here, but as far as I know there are plenty of situations in this corner of Europe where mental health issues have been dealt with appropriately and medicals have been reinstated or retained. There appears to be more of a bias against discussing this with an AME on the US side of the pond, but I'm sure there are good and bad examples of situations on both sides.
The basis of the relationship between a licence holder and an AME is don't hold back any information. Be honest, be clear about what's troubling you and as you mentioned, I'm sure you will be seen in a positive light. At least, you should be. If you're part of a union, talk to them, see if they can offer any assistance throughout the process. They may be able to provide support, either legal or professional or both, and in the end they're on your side. Don't forget, so is the AME. You're both in it for the same reason: keeping air travel safe.